Racial differences in the relationship between tobacco, alcohol, and the risk of head and neck cancer: pooled analysis of US studies in the INHANCE Consortium.

There have been few published studies on differences between Blacks and Whites in the estimated effects of alcohol and tobacco use on the incidence of head and neck cancer (HNC) in the United States. Previous studies have been limited by small numbers of Blacks. Using pooled data from 13 US case-control studies of oral, pharyngeal, and laryngeal cancers in the International Head and Neck Cancer Epidemiology Consortium, this study comprised a large number of Black HNC cases (n = 975). Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for several tobacco and alcohol consumption characteristics. Blacks were found to have consistently stronger associations than Whites for the majority of tobacco consumption variables. For example, compared to never smokers, Blacks who smoked cigarettes for > 30 years had an OR 4.53 (95% CI 3.22-6.39), which was larger than that observed in Whites (OR 3.01, 95% CI 2.73-3.33; p _interaction  < 0.0001). The ORs for alcohol use were also larger among Blacks compared to Whites. Exclusion of oropharyngeal cases attenuated the racial differences in tobacco use associations but not alcohol use associations. These findings suggest modest racial differences exist in the association of HNC risk with tobacco and alcohol consumption.